Conventional rectangular concrete tank construction makes extensive use of wood formwork to define vertical walls and steel reinforcing bars which extend from slabs and adjacent walls to facilitate the joining of walls to the slab or adjacent walls to each other. The use of conventional rectangular concrete tank construction has many drawbacks. First, conventional rectangular concrete tank construction creates extreme safety hazards for construction personnel. Extending reinforcing steel at best creates a tripping hazard and at worst an instrument for severe injury to workers. Conventional rectangular concrete tank construction often requires workers to climb reinforcing steel and formwork which are not intended to support construction personnel, creating a risk of falling. Furthermore, the use of cranes to “fly-in” reinforcing steel, formwork and concrete creates obvious overhead hazards. Moreover, the piece-meal nature of conventional rectangular concrete tank construction creates a myriad of other specific hazards associated with the necessary carpentry, concrete finishing, and reinforcement placement trades, including formwork clutter, extensive small tool usage, extension cords and cutting tools, to name but a few.
Second, the extensive use of wood formwork in conventional rectangular concrete tank construction also raises environmental issues. The amount of wood formwork wasted in the construction of a medium to large sized rectangular tank can equate to enough lumber to build several homes.
Third, conventional rectangular concrete tank construction techniques inherently create the potential for concrete defects such as misaligned concrete panels and concrete consolidation problems. Furthermore, water leakage problems associated with shrinkage, cracking, tie holes, water stop installation and the use of construction and expansion joints are commonplace.
Further problems with conventional rectangular concrete tank construction include high labor costs, high material costs and equipment usage costs and sequencing difficulties caused by the need to stagger concrete panel placements to prevent shrinkage cracking. Furthermore, efficient access to the construction site for workers and equipment is severely hampered by protruding reinforcing dowels. In addition, stripping formwork at the construction site can be hazardous because of protruding reinforcing. Moreover, curing of vertical concrete surfaces can be difficult and a substantial amount of finishing work may be required after the concrete has been poured.
The rectangular concrete tilt-up tank construction of the present invention is intended to overcome one or more of the problems discussed above.